At present, data cards generally need to be equipped in various kinds of electronic products to implement specific functions. For example, a mobile terminal (for example, a mobile phone) needs to be equipped with a SIM (Subscriber Identity Module, subscriber identity module) card for use. A chip of the SIM card stores content, such as information about a digital mobile phone user, an encryption key, and a phonebook of the user, which can be used for authenticating an identity of the digital mobile network user and encrypting voice information during a call of the user.
At present, SIM cards are classified into standard SIM cards, MicroSIM cards (micro-SIM card), and MiniSIM cards (mini-SIM card). Their basic functions are the same, but their sizes vary obviously. The standard SIM card and the micro-SIM card are used as an example. Table 1 shows key outline sizes of the standard SIM card and the micro-SIM card. It can be seen from the following comparison that their basic outline sizes are all different, but their electrical contacts are the same in size and spacing; therefore card connectors used to fasten the SIM cards are totally different in outline sizes, but metal pins, on the card connectors, in contact with the electrical contacts of the foregoing standard SIM card and micro-SIM card are the same.
TABLE 1SizeSIM CardMicro SIM CardOutline length25 mm15 mmOutline width15 mm12 mmOutline corner cutting 3 mm2.5 mm Contact size  2 mm * 1.7 mm  2 mm * 1.7 mmContact spacing5.62 mm * 0.84 mm5.62 mm * 0.84 mm
Even if the electrical contacts are the same, because the outline sizes are different, at present, special attention needs to be paid to designs of the card connectors for the two types of SIM cards in the industry.
As shown in FIG. 1, FIG. 1 is a standard SIM card connector that is provided with a locking mechanism, and the standard SIM card connector is suitable for insertion of a standard SIM card. As shown in FIG. 2, FIG. 2 is a micro-SIM card connector that is suitable for insertion of a micro-SIM card.
Disadvantages of the card connectors are that one type of card connector is suitable for insertion of only one corresponding type of SIM card and cannot match different SIM cards, and that different card connectors are applied to different main boards. Therefore, in the prior art shown in FIG. 1 and FIG. 2, only one card connector and one SIM card matching the card connector can be disposed on one terminal.
As an improvement, another prior art further puts forth that two different types of card connectors, such as a card connector suitable for a standard SIM card and a card connector suitable for a micro-SIM card, may be applied to a same main board of one terminal, and one of the two card connectors can be selected for use. Therefore, in this prior art, two card connectors and two SIM cards respectively corresponding to the card connectors can be disposed on one terminal. However, for a same card connector, it is still impossible that the same card connector is compatible with two types of SIM cards.
In addition, in still another prior art, a micro-SIM card is enclosed in a plastic card adapter, so that a size of the micro-SIM card can be expanded to that of a standard SIM card. Compared with the foregoing prior arts, this manner is more compatible and more convenient, but is disadvantageous in that the card adapter requires secondary assembly, where both card adapter tolerance and assembly tolerance are likely to cause poor assembly. In addition, a standard SIM card requires relatively high assembly precision. As a result, the micro-SIM card is likely to fall loose and consequently cannot be used normally. In addition, this type of card adapter needs to be additionally purchased by a user, which is not convenient enough for use.
Although the foregoing discusses card connectors, the inventor also finds that other bases for insertion of devices, similar to a card connector, also have the problem that a same base is not compatible with different devices.